Carburetor



May 21, 1929. F. E. LONAS ET AL 1,713,705

CARBURETOR Filed March 1 1922 2 sheets-sheet 1 extreme movement of the valve needle 30, or'

approximately so, and when the parts are in the position shown in Fig. 1 the valve needle closes or practically closes the passage Extending radially from the top .of the enlarged portion 36 of the bore 29 are a plu- :1 'rality of radial fuel discharge ports 38 which form a comn'iunication between the enlargement 36 ofsaid bore and the fuel passage 25.

' The bottom of the bore 35 is placed in communication with the fuel chamber 18 near the bottom thereof by a plurality of radial ports 39 which are preferably located below a fuel strainer 40 mounted on the cap 17, as clearly shown in Fig. 1 of the drawing. The fuel controlling device 35 may be adjusted by grasping a large milled head 41 at'the lower end thereof and turning same to the desired position where it may be held'bya lock nut 42. The plug 22 extends downwardly into the top of the fuel chamber 18, as shown at 43, and is provided with a tapered seat 44. A plurality of bores 45 extend from the approximate center of said seat upwardly through the plug, as clearly shown in Fig. 1, and four of these bores are preferably employed. The

combined area of said bores'is sufficient to maintain under alloperatmg condltions of the carburetor, a substantially fixed level of fuel in the fuel chambena. Cooperating with the seat 44 is a tapered valve 46 carried by a float 47 mounted in the fuel chamber 18, and

said float is guided by and slidably movable on the fuel controlling device 35, as clearly shown in Fig. I

Surrounding the extens1on'43 and spaced therefromis an upwardly directed tubular member 48 carried "bythe float 47, which serves to preventany possible chance of fuel passing upwardly through the bores 45 between the valve 46 and seat 44 in the event of the fuel raisingimomentarily above a predetermined level which willbe 'fixed by the operation of saidfloat.

In the construction shown in Fig. 1, the

'valve 33-seats upon the top of the tubular extension 21 as shown at 49, and below this point the valve istapered or flared outwardly as shown at 50 so as to control the admission of air to the mixing chamber as 'sa-id'valve rises in thecasing 10.- As the valve rises the valve needle 30 is correspondingly raised and cooperates with the tapered bore37 of the fuel controlling device 35 to permit the passage of an amount of fuel proportionate to the air as will beapparent. J i

In Fig. 1 of'the drawing, the various parts ofourzimprovement are shown man 1noperativeposition and, if the butterfly valve 12 is slightly open and the engine started in the usual manner, fuel will bedrawn into the valve chamber 18 through the admission port 19 from a fuel tank or reservoir at a lower level by the suction through the bores 45 as well as through the tapered bore 37, and as the fuel rises in the fuel chamber 18 the float 26 and discharged into the mixing chamberp 27 through the fine openings formed by the knurling 28, and a proportionate amount of airwill be drawn into said mixing chamber through the air port formed by the taper 50 of the valve 33. I r

In the operation of our carburetor the float 47 and valve 46 will assume a-position which will leave open'suificient suction passage area to replenish the fuel as fast as discharged from the fuel chamber into the mixing chamber, and thus maintain a substantially unchanging fuel level in the fuel chamber. case of a suddenly increased opening of the throttle causinga drop in the fuel level the drop of'the valve 46 away from its seat will instantly increase the suction area between them, and a corresponding increase of fuel 'flow willrestore and maintain the necessary level of fuel in the fuel chamber to supply the increased qiuantity of fuel required by such increased throttle opening. Thus the float and valve "will fluctuate within very narrow limits of' vertical movement and at all times maintain just sufficient suction opening to supply fuel as fast as discharged from the fuel to the mixing chamber.

In other words, the float 4'!" andt-hevalve 46 thereon will fluctuate slightly to at all times compensate for and maintain a substantially fixed fuel level in the fuel chamber 18 to meet the varying requirements of the motor. With a carburetor of this construction, at all times, and regardless of the level of fuel in the fuel storage tank, and regardless of the operating conditions of the vehicle, whether traveling on a level road-way or a grade, the operative parts of the carburetor and mainly the valve 46 and float 47 will automatically operate to control the exposed suction area to maintain under the aforesaid conditions a substantially fixed level in the. fuel chamber of the car-bu rotor; in otlier w'oros, under all operating conditions the fuel'is drawn into the mixing chamber 27 of the carburetor from a substantiallyrfixed fuel level in the fuel chamber 118.

1 In the above described operation, it will be understood that the increased velocity of flow of air past the fuel discharge, which is produced by the tapered face of the valve forming a Venturi throat, creates a greater depression at the fuel discharge, causing the fuel to be lifted from the fuel chamber netwithstanding the suction action which takes place in the suction passages opening into said fuel chamber.

In the construction shown in Figs. 1- to 6 inclusive, we have shown a slight modification in the general. design of the carburetor and in Fig. f, it will be noted that the supplemental casing 1.5, or the base'thereof, fits within and is removable from the base of the main casing 10 as shown at 51, and the cap 17 is omitted and substituted therefor is a cupshapcd casing 52 in which the fuel chamber 18 is formed.

it will also be noted thata sleeve is mounted in the top portion of the casing 10 and extends downwardly into the mixing chamber. and operates in connection with the valve 33 to form a dash-pot for said valve, and also serves to maintain a substantially fixed area through the carluiretor and avoids the expansion of the fuel mixture above the valve which would be the case in the construction shown in Fig. 1.

In Figs. 4 to 6 inclusive, the adjustable fuel controlling device 35 also is omitted, and in said figures, we provide a sleeve extension to the valve to on the float 47. This sleeve extension, or the bore thereof, is tapered atthe upper end as shown at :36, and the valve needle 30 operates in connection with the tapered bore 56 to control the fuel as it passes therethrough. The sleeve extension 55 is provided in the periphery thereof with a plurality of flutes 5'? which form between said sleeve and the enlargement 36 in the bore 29 suction passages, controlled by the valve to on the float operating in connection with the beveled seat in the construction shown in 1.

In the construction shown Figs. 4- to 6 inclusive, it will beapparent that the suction passages 57 as well as the fuel passage lead to a common discharge or opening into the mixing chamber instead of through two independent openings or discharges as in Figs. 1 to 3 inclusive, but the operation of the consiitruction shown in Figs. 4: to 6 inclusive will be precisely the same as that shown in Figs. 1 to 8 inclusive, the only difference being that as the float 4:7 and valve l-ti rise the flutes or suction passages 57 are gradually reduced in area or finally sealed by the operation of the valve 46 in connection with the seat 4st.

In both forms of construction where the valve needle 30 passes through the central body 32 of the valve 33 a slight clearance is provided to facilitate the self-alinemcntof said valve needle in the bore 29 thus providing for a free action of the valve 33 at all tunes avoiding any possibility of sticking thereof.

It will also be apparent that while we have shown the fuel chamber as incorporated in, or contained within, the general structure of the carburetor that the fuel chamber may be independent of the carburetor casing, or'be located externally thereof as is a common custom in the art to which this invention relates, and while we have shown in the accompanying drawings certain details of construction for carrying our invention into effect, it will be understood that we are not necessarily limited to these details, and various changes therein and modifications thereof may be made, within the scope of the appended claims, without departing from the spirit of our invention or sacrificing its advantages;

Having fully described our inventionywhat we claim as new and desire to secure by Letters Patent, is

1. in a carburetor having a member operated by the engine suction for maintaining a substantially constant depression at the fuel disclmrge into the mixing chamber of the carlniretor. a fuel chamber below said fuel dischiurge, said member including means con trolling the transmission of fuel from the fuel chamber to said fuel discharge, means including a float actuated valve and a port controlled by said valve for placing the fuel chamber in communication with the mixing chamber, whereby fuel may be drawn from a reservoir at a lower level to said fuel chamber to maintain a substantially fixed fuel level in said fuel chamber below said fuel discharge.

2. In a carburetor having a member operated by the engine suction for maintaining a substantially constant depression at the fuel discharge into the mixing chamber of the carburetor, a fuel chamber below said fuel discharge, said member including means controlling the transmission of fuel from the fuel chamber to said fuel. discharge, means including a float actuated valve and a port controlled by said valve for placing the fuel chamber in connnunication with the mixing chamber, whereby fuel may be drawn from a reservoir at a lower level to said fuel chamber to maintain a substantially fixed fuel level in said fuel chamber below said fuel discharge, said member and second named means cooperating to provide a supply to the mixing chamber of an unvarying mixture of fuel and air.

3. A'suction feed carburetor comprising a fuel chamber, a mixing chamber positioned entirely above the fuel chamber, a suction passage placing said chambers in communication, a fuel discharge opening into the mixing chamber and in communication with said fuel chamber, a combined air and fuel valve operated by engine suction for supplying an unvarying ratio of fuel and air to the mixing chamber and forcreating adepression in said suction passage to raisefuel from a fuel storage at a loWer level. to said fuel chamber and maintaining a substantially fixed level in said chamber by the action of said automatically operated means.

4. In a vacuum feed carburetor having a mixing chamber and a fuel chamber below the mixing chan'iber, independent passagesplacing said chambers in communication, one of said passages constituting a fuel discharge passage and opening into the mixing chamber at a point below the other passage, the first named passage opening into the lower end portion of the fuel'chamber andthe second I namedpassage openi 11g into the upper end of said chamber, a member operated by the suc-' tion' of the engine controllingthe admission of air to the mixing chamber and the passage of fuel from the fuel chamber into the mixing chamber through said first named passage,

and means involving an automatically oper-' ated valve for controlling thesecond named passage for regulating the transmission of fuel from a fuel storage tankat arlower level to the mixing chamber of the carburetor and for, malntaimng a substantially fixed-level of fuelin said fuel chamber at a point below the communication of the second named passage with sa d fuel chamber.

5. A'carburetor having mixingand fuel chambersplaced in communication by a suction passage, the fuel chamber being positioned below the mixing chamber, means for maintaining a substantially unvarying vacuum in the mixing chamber, whereby fuel may be drawn from a fuelstorage at alower level to the fuel chamber and supplied to said mixing chamber, a float actuated valve in the fuel chambercontrolling said suction passage to maintain. a substantially constant level of fuel in the fuel chamber, and a fuel discharge passage opening into the lower end portion ofv the fuelchamber and into. said mixing chamber whereby fuel may be supplied to the mixing chamber in the operation ofsaid first named means.

6. A carburetor having mixing and fuel chambers placed in communication by a suction passage, the fuel chamber being p ositioned below the mixingchamber, means for maintaining a substantially unvaryin g vacuum in the mixing chamber, whereby fuel may be drawn from a fuel storage at arlower level to the fuel chamber and supplied to'saidmixmg chamber, afloat actuatedvalve 1n the fuel chamber controllingsaid suction passage to maintain a substantially constant level of.

1 at a point above the level of fuel maintained therein.

7. In a carburetor having a fuel chamber positioned below the fuel discharge-into the mixing chamber ofthe carburetor, means for placing the fuel discharge in communication with said fuel chamber, a suctlon passage expose-d to the mixing chamber and opening into the upper end of saidfuel chamber above the level of fuel therein, a float actuated valver in the fuel chamber and cooperating with said suction passage to maintain substantially fixed fuel level in said fuelchamber and be low said fuel discharge, and a valve movable relatively tosaid fuel discharge to createa depression at the fuel discharge to lift fuel from said chamber for supply to the mixing chamber of the carburetor.

In testimony that We claim the foregoing as our invention, we have signed our names,

this 28th day of February, 1922.

' v i FRANK E, LONAS.

'HOvVARD THOMPSON. 

